# Find the equation of the normal to the curve at the point (1,49)

• May 23rd 2010, 08:58 AM
ansonbound
Find the equation of the normal to the curve at the point (1,49)
c) Find the equation of the normal to the curve at the point (1,49)
Quote:

The slope of the tangent at x=1 is

http://www.mathhelpforum.com/math-he...d6f67eaf-1.gif

The normal is perpendicular to the tangent, hence invert and negate the tangent slope

The slope of the normal is -1/45 and the normal contains the point (1,49)

Hence, the normal equation at that point is

http://www.mathhelpforum.com/math-he...1ab0b824-1.gif
How do i know the slope of the normail is -1/45?
• May 23rd 2010, 09:09 AM
e^(i*pi)
Quote:

Originally Posted by ansonbound
c) Find the equation of the normal to the curve at the point (1,49)

How do i know the slope of the normail is -1/45?

Because the normal is defined as being perpendicular to the tangent and for two perpendicular lines $m_1m_2 = -1$